1. Technical Field
The present invention relates to an electro-optic apparatus and a control method thereof.
2. Related Art
A liquid crystal display apparatus is provided such that, in a pair of substrates, pixel electrodes are arranged in the matrix shape for respective pixels on one substrate and a counter electrode is common to the respective pixels on the other substrate. Furthermore, liquid crystal is configured to be interposed between the pixel electrodes and the counter electrode. In the configuration, if a voltage according to grayscale to be displayed is applied and maintained between the pixel electrodes and the counter electrode, the orientation states of liquid crystal molecules are defined for the respective pixels. Therefore, the transmittance or the reflectance of the pixels is controlled. Generally, time is taken from when a voltage is applied to the liquid crystal to when the orientation states of the liquid crystal molecules are changed, and thus there are cases in which a response speed is low and a response is not ended during a writing time corresponding to a frame frequency in the liquid crystal display apparatus. In order to solve the problem, an overdrive process has been known which causes a response to be ended in one frame by comparing an image signal before one frame with an image signal of a current frame and compensating for a voltage which is higher (lower) than a drive voltage that is necessary for transition to a target transmittance (refer to Japanese Patent No. 2616652).
However, as a method of increasing pseudo-resolution, in a projector or the like, pixel shift is known in which an optical path shifting element that optically shifts a display position is used. In the pixel shift, one frame is divided into a plurality of unit periods, and the optical path shifting element is controlled such that pixel shift states are different from each other for the respective unit periods. If the above-described overdrive process is applied to the pixel shift without change, an image signal which is used for the overdrive process is generated based on an image signal, which is acquired by delaying an image signal to be input by one frame, and a current image signal.
However, in the pixel shift, an image signal which is supplied to a liquid crystal panel is generated for each unit period based on the input image signal. Accordingly, even when the overdrive process is performed based on the image signal to be input and an image signal before one frame thereof, there is a problem in that it is difficult to apply the overdrive process to the pixel shift.